There are a number of conventional processes for packaging integrated circuits. Many packaging techniques use a lead frame that has been stamped or etched from a metal sheet to provide electrical interconnects to external devices. A die is electrically connected to portions of the lead frame via bonding wires or other suitable electrically connections. Generally, the die, lead frame and bonding wires are then encapsulated in a mold while leaving selected portions of the lead frame exposed to facilitate electrical connection to external devices.
There are a number of processes for encapsulating such IC packages. One relatively recently developed encapsulation process is film-assisted molding. In film-assisted molding, the bottom surface of the lead frame is not pre-taped prior to encapsulation, rather, the lead frame is positioned on an adhesive film. A package specific lamination tool then presses on designated portions of the lead frame to ensure good adhesion between the adhesive film and the lead frame. The adhesive film then prevents molding compound from covering the portions of the lead frame that are in contact with the adhesive film during encapsulation. After the molding compound has cured, the encapsulated lead frame and film are removed from the mold and the film is peeled off of the lead frame.
Although existing film-assisted molding techniques, and others, work well, there are continuing efforts to develop even more efficient designs and methods for encapsulating integrated circuits.